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1.
J Sci Food Agric ; 2024 Sep 17.
Artículo en Inglés | MEDLINE | ID: mdl-39287449

RESUMEN

BACKGROUND: Saffron petals are usually considered as waste after saffron harvest. However, saffron petals contain many important phytochemical components (e.g. quercetin and kaempferol), which may alleviate oxidative damage in human cells. RESULTS: The contents of flavonoids and crocin in different parts of saffron were analyzed. The protective effects of flavonoids from saffron on oxidative damage of B16 cells were investigated. Saffron stigma contained high contents of crocin and picrocrocin, whereas flavonoid content (quercetin, 4.03 ± 0.33 mg g-1 DW; kaempferol, 47.80 ± 0.60 mg g-1 DW) was higher in saffron petals than in other parts. Incubation of B16 cells with quercetin (10-30 µmol L-1) and kaempferol (20-30 µmol L-1) obtained from saffron extracts could significantly increase the total antioxidant capacity (T-AOC) and the activity of NADPH:dehydrogenase quinone-1 (NQO1) to alleviate H2O2-induced oxidative damage. Quercetin was better than kaempferol in increasing NQO1 activity and T-AOC. Quercetin extracted from saffron petals could induce NQO1 expression through regulating kelch-like ECH-associated protein-1/nuclear factor erythroid 2-related factor-2 signaling pathway to protect B16 cells from oxidative damage. CONCLUSION: The content of kaempferol-3-O-sophoroside and quercetin-3-O-sophoroside was higher in saffron petals than in other parts of saffron. The kaempferol and quercetin obtained from saffron petals could enhance the activity of antioxidant enzyme NQO1 and T-AOC in B16 cells. This indicated that saffron petals, as a potential functional food, may prevent diseases caused by oxidative stress. © 2024 Society of Chemical Industry.

2.
Biophys J ; 2024 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-39126157

RESUMEN

The nucleus of eukaryotic cells is constantly subjected to different kinds of mechanical stimuli, which can impact the organization of chromatin and, subsequently, the expression of genetic information. Experiments from different groups showed that nuclear deformation can lead to transient or permanent condensation or decondensation of chromatin and the mechanical activation of genes, thus altering the transcription of proteins. Changes in chromatin organization, in turn, change the mechanical properties of the nucleus, possibly leading to an auxetic behavior. Here, we model the mechanics of the nucleus as a chemically active polymer gel in which the chromatin can exist in two states: a self-attractive state representing the heterochromatin and a repulsive state representing euchromatin. The model predicts reversible or irreversible changes in chromatin condensation levels upon external deformations of the nucleus. We find an auxetic response for a broad range of parameters under small and large deformations. These results agree with experimental observations and highlight the key role of chromatin organization in the mechanical response of the nucleus.

3.
Comput Methods Programs Biomed ; 255: 108331, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39068872

RESUMEN

BACKGROUND AND OBJECTIVE: Immune cell migration is one of the key features that enable immune cells to find invading pathogens, control tissue damage, and eliminate primary developing tumors. Chimeric antigen receptor (CAR) T-cell therapy is a novel strategy in the battle against various cancers. It has been successful in treating hematological tumors, yet it still faces many challenges in the case of solid tumors. In this work, we evaluate the three-dimensional (3D) migration capacity of T and CAR-T cells within dense collagen-based hydrogels. Quantifying three-dimensional (3D) cell migration requires microscopy techniques that may not be readily accessible. Thus, we introduce a straightforward mathematical model designed to infer 3D trajectories of cells from two-dimensional (2D) cell trajectories. METHODS: We develop a 3D agent-based model (ABM) that simulates the temporal changes in the direction of migration with an inverse transform sampling method. Then, we propose an optimization procedure to accurately orient cell migration over time to reproduce cell migration from 2D experimental cell trajectories. With this model, we simulate cell migration assays of T and CAR-T cells in microfluidic devices conducted under hydrogels with different concentrations of type I collagen and validate our 3D cell migration predictions with light-sheet microscopy. RESULTS: Our findings indicate that CAR-T cell migration is more sensitive to collagen concentration increases than T cells, resulting in a more pronounced reduction in their invasiveness. Moreover, our computational model reveals significant differences in 3D movement patterns between T and CAR-T cells. T cells exhibit migratory behavior in 3D whereas that CAR-T cells predominantly move within the XY plane, with limited movement in the Z direction. However, upon the introduction of a CXCL12 chemical gradient, CAR-T cells present migration patterns that closely resemble those of T cells. CONCLUSIONS: This framework demonstrates that 2D projections of 3D trajectories may not accurately represent real migration patterns. Moreover, it offers a tool to estimate 3D migration patterns from 2D experimental data, which can be easily obtained with automatic quantification algorithms. This approach helps reduce the need for sophisticated and expensive microscopy equipment required in laboratories, as well as the computational burden involved in producing and analyzing 3D experimental data.


Asunto(s)
Movimiento Celular , Hidrogeles , Linfocitos T , Humanos , Linfocitos T/citología , Linfocitos T/inmunología , Hidrogeles/química , Receptores Quiméricos de Antígenos/metabolismo , Simulación por Computador , Algoritmos , Inmunoterapia Adoptiva/métodos
4.
Foods ; 13(13)2024 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-38998517

RESUMEN

This study aimed to analyse the impact of a simulated human digestion process on the composition and functional properties of dietary fibres derived from pomegranate-peel, tomato-peel, broccoli-stem and grape-stem by-products. For this purpose, a computer-controlled simulated digestion system consisting of three bioreactors (simulating the stomach, small intestine and colon) was utilised. Non-extractable phenols associated with dietary fibre and their influence on antioxidant capacity and antiproliferative activity were investigated throughout the simulated digestive phases. Additionally, the modifications in oligosaccharide composition, the microbiological population and short-chain fatty acids produced within the digestion media were examined. The type and composition of each dietary fibre significantly influenced its functional properties and behaviour during intestinal transit. Notably, the dietary fibre from the pomegranate peel retained its high phenol content throughout colon digestion, potentially enhancing intestinal health due to its strong antioxidant activity. Similarly, the dietary fibre from broccoli stems and pomegranate peel demonstrated anti-proliferative effects in both the small and the large intestines, prompting significant modifications in colonic microbiology. Moreover, these fibre types promoted the growth of bifidobacteria over lactic acid bacteria. Thus, these results suggest that the dietary fibre from pomegranate peel seems to be a promising functional food ingredient for improving human health.

5.
EClinicalMedicine ; 67: 102362, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38125965

RESUMEN

Background: Understanding and optimising mental health and psychosocial support (MHPSS) interventions in humanitarian crises is crucial, particularly for the most prevalent mental health conditions in conflict settings: anxiety, depression, and post-traumatic stress disorder. However, research on what is the most appropriate length of psychological intervention is lacking in this setting. We aimed to establish which factors are most closely related to improvement and to determine the required number of consultations needed to achieve this improvement. Methods: We retrospectively analysed records from 9028 patients allocated to treatment for anxiety, depression, and post-traumatic symptoms from the MHPSS programme in Borno State, Nigeria, from January 2018 to December 2019. Patient characteristics, severity (Clinical Global Impression of Severity Scale, CGI-S scale), and clinical improvement were assessed by an attending counsellor (CGI-I scale) and by the patient (Mental Health Global State, MHGS scale). Improvement was defined as scores 1, 2, and 3 in the Clinical Global Impression of Improvement (CGI-I) scale, and as a decrease of at least 4 points in the MHGS scale. We investigated the associations between the category of symptoms, the severity of illness, and improvement of symptoms using multivariable logistic regression. We used Kaplan-Meier (KM) curves to assess the number of consultations (i.e., time of treatment) needed to achieve improvement of symptoms, by symptom category and symptom severity. Findings: The patients included were referred to treatment for anxiety (n = 3462), depression (n = 3970), or post-traumatic symptoms (n = 1596). Median age was 31 years (range 16-103), and 84.3% were female. Patients categorised as severe were less likely to present improvement according to the CGI-I scale (OR 0.11, 95% CI 0.05-0.25), while none of the other categories of symptoms showed significant results. Overall, three or more consultations were associated with improvement in both scales (OR 3.55, 95% CI 1.47-8.57 for CGI-I; and OR 3.04, 95% CI 2.36-3.90 for MHGS). KM curves for the category of symptoms showed that around 90% of patients with anxiety, depression, or post-traumatic symptoms, as well as those with mild or moderate severity, presented improvement after three consultations, compared with six consultations for those with severe symptoms. Interpretation: Classification by severity among patients with anxiety, depression, or post-traumatic symptoms could predict the probability of improvement, whereas classification by symptoms could not. Our study highlights the importance of classifying patient severity in MHPSS programmes to plan and implement the appropriate duration of care. A major limitation was the number of patients lost to follow up after the first consultation and excluded from the logistic regression and KM analysis. Funding: The study was funded and staffed entirely by Médicos Sin Fronteras (Médecins Sans Frontières), Spain.

6.
J Agric Food Chem ; 71(49): 19189-19206, 2023 Dec 13.
Artículo en Inglés | MEDLINE | ID: mdl-37963243

RESUMEN

The production of saffron spice results in numerous byproducts, as only 15 g of spice can be produced from 1 kg of flowers, indicating that over 90% of the saffron flower material is eventually discarded as waste. In view of this, the paper reviews current knowledge on the natural active components in saffron byproducts and their biological activities, aiming to lay a theoretical and scientific foundation for the further utilization. Saffron byproducts contain a variety of phytochemical components, such as flavonoids, anthocyanins, carotenoids, phenolic acids, monoterpenoids, alkaloids, glycosides, and saponins. The activities of saffron byproducts and their mechanisms are also discussed in detail here.


Asunto(s)
Productos Biológicos , Crocus , Antocianinas , Extractos Vegetales/farmacología , Carotenoides , Antioxidantes , Flores , Colorantes
7.
Malar J ; 22(1): 345, 2023 Nov 10.
Artículo en Inglés | MEDLINE | ID: mdl-37950227

RESUMEN

BACKGROUND: Seasonal malaria chemoprevention (SMC) using sulfadoxine-pyrimethamine plus amodiaquine (SP-AQ), is a community-based malaria preventive strategy commonly used in the Sahel region of sub-Saharan Africa. However, to date it has not been implemented in East Africa due to high SP resistance levels. This paper is a report on the implementation of SMC outside of the Sahel in an environment with a high level of presumed SP-resistance: five cycles of SMC using SPAQ were administered to children 3-59 months during a period of high malaria transmission (July-December 2019) in 21 villages in South Sudan. METHODS: A population-based SMC coverage survey was combined with a longitudinal time series analysis of health facility and community health data measured after each SMC cycle. SMC campaign effectiveness was assessed by Poisson model. SPAQ molecular resistance markers were additionally analysed from dried blood spots from malaria confirmed patients. RESULTS: Incidence of uncomplicated malaria was reduced from 6.6 per 100 to an average of 3.2 per 100 after SMC administration (mean reduction: 53%) and incidence of severe malaria showed a reduction from 21 per 10,000 before SMC campaign to a mean of 3.3 per 10,000 after each cycle (mean reduction: 84%) in the target group when compared to before the SMC campaign. The most prevalent molecular haplotype associated with SP resistance was the IRNGE haplotype (quintuple mutant, with 51I/59R/108N mutation in pfdhfr + 437G/540E in pfdhps). In contrast, there was a low frequency of AQ resistance markers and haplotypes resistant to both drugs combined (< 2%). CONCLUSIONS: The SMC campaign was effective and could be used as an additional preventive tool in seasonal malaria settings outside of the Sahel, especially in areas where access to health care is unstable. Malaria case load reduction was observed despite the high level of resistance to SP.


Asunto(s)
Antimaláricos , Malaria , Niño , Humanos , Antimaláricos/farmacología , Antimaláricos/uso terapéutico , Sudán del Sur , Estaciones del Año , Malaria/epidemiología , Malaria/prevención & control , Malaria/tratamiento farmacológico , Quimioprevención , Morbilidad , Resistencia a Medicamentos/genética
8.
Am J Trop Med Hyg ; 109(5): 1072-1076, 2023 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-37748765

RESUMEN

Artemisinin-combined treatments are the recommended first-line treatment of Plasmodium falciparum malaria, but they are being threatened by emerging artemisinin resistance. Mutations in pfk13 are the principal molecular marker for artemisinin resistance. This study characterizes the presence of mutations in pfk13 in P. falciparum in Western Equatoria State, South Sudan. We analyzed 468 samples from patients with symptomatic malaria and found 15 mutations (8 nonsynonymous and 7 synonymous). Each mutation appeared only once, and none were validated or candidate markers of artemisinin resistance. However, some mutations were in the same or following position of validated and candidate resistance markers, suggesting instability of the gene that could lead to resistance. The R561L nonsynonymous mutation was found in the same position as the R561H validated mutation. Moreover, the A578S mutation, which is widespread in Africa, was also reported in this study. We found a high diversity of other pfk13 mutations in low frequency. Therefore, routine molecular surveillance of resistance markers is highly recommended to promptly detect the emergence of resistance-related mutations and to limit their spread.


Asunto(s)
Antimaláricos , Artemisininas , Malaria Falciparum , Humanos , Plasmodium falciparum/genética , Antimaláricos/farmacología , Antimaláricos/uso terapéutico , Sudán del Sur , Proteínas Protozoarias/genética , Resistencia a Medicamentos/genética , Artemisininas/farmacología , Artemisininas/uso terapéutico , Malaria Falciparum/tratamiento farmacológico , Malaria Falciparum/epidemiología , Mutación
9.
iScience ; 26(7): 107164, 2023 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-37485358

RESUMEN

How cells orchestrate their cellular functions remains a crucial question to unravel how they organize in different patterns. We present a framework based on artificial intelligence to advance the understanding of how cell functions are coordinated spatially and temporally in biological systems. It consists of a hybrid physics-based model that integrates both mechanical interactions and cell functions with a data-driven model that regulates the cellular decision-making process through a deep learning algorithm trained on image data metrics. To illustrate our approach, we used data from 3D cultures of murine pancreatic ductal adenocarcinoma cells (PDAC) grown in Matrigel as tumor organoids. Our approach allowed us to find the underlying principles through which cells activate different cell processes to self-organize in different patterns according to the specific microenvironmental conditions. The framework proposed here expands the tools for simulating biological systems at the cellular level, providing a novel perspective to unravel morphogenetic patterns.

10.
Foods ; 12(9)2023 Apr 27.
Artículo en Inglés | MEDLINE | ID: mdl-37174358

RESUMEN

This study identified the compounds obtained from four native Dehesa plants, which were holm oak, elm, blackberry and white rockrose, and evaluated their ability to inhibit the growth and production of aflatoxins B1 and B2 of two strains of mycotoxigenic Aspergillus flavus. For this purpose, phenolic compounds present in the leaves and flowers of the plants were extracted and identified, and subsequently, the effect on the growth of A. flavus, aflatoxin production and the expression of a gene related to its synthesis were studied. Cistus albidus was the plant with the highest concentration of phenolic compounds, followed by Quercus ilex. Phenolic acids and flavonoids were mainly identified, and there was great variability among plant extracts in terms of the type and quantity of compounds. Concentrated and diluted extracts were used for each individual plant. The influence on mold growth was not very significant for any of the extracts. However, those obtained from plants of the genus Quercus ilex, followed by Ulmus sp., were very useful for inhibiting the production of aflatoxin B1 and B2 produced by the two strains of A. flavus. Expression studies of the gene involved in the aflatoxin synthesis pathway did not prove to be effective. The results indicated that using these new natural antifungal compounds from the Dehesa for aflatoxin production inhibition would be desirable, promoting respect for the environment by avoiding the use of chemical fungicides. However, further studies are needed to determine whether the specific phenolic compounds responsible for the antifungal activity of Quercus ilex and Ulmus sp. produce the antifungal activity in pure form, as well as to verify the action mechanism of these compounds.

11.
Comput Biol Med ; 159: 106895, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-37060771

RESUMEN

To unravel processes that lead to the growth of solid tumours, it is necessary to link knowledge of cancer biology with the physical properties of the tumour and its interaction with the surrounding microenvironment. Our understanding of the underlying mechanisms is however still imprecise. We therefore developed computational physics-based models, which incorporate the interaction of the tumour with its surroundings based on the theory of porous media. However, the experimental validation of such models represents a challenge to its clinical use as a prognostic tool. This study combines a physics-based model with in vitro experiments based on microfluidic devices used to mimic a three-dimensional tumour microenvironment. By conducting a global sensitivity analysis, we identify the most influential input parameters and infer their posterior distribution based on Bayesian calibration. The resulting probability density is in agreement with the scattering of the experimental data and thus validates the proposed workflow. This study demonstrates the huge challenges associated with determining precise parameters with usually only limited data for such complex processes and models, but also demonstrates in general how to indirectly characterise the mechanical properties of neuroblastoma spheroids that cannot feasibly be measured experimentally.


Asunto(s)
Hidrogeles , Neuroblastoma , Humanos , Porosidad , Teorema de Bayes , Microambiente Tumoral
12.
Artículo en Inglés | MEDLINE | ID: mdl-36767025

RESUMEN

The aim of this work was to determine the antimicrobial activity of the essential oils of six plants widely distributed in the Dehesa of Extremadura, such as Calendula officinalis, Cistus ladanifer, Cistus salviifolius, Cistus multiflorus, Lavandula stoechas, and Rosmarinus officinalis. The content of total phenolic compounds (TPC) and the antimicrobial activity of the essential oils against pathogenic and spoilage bacteria and yeasts as well as aflatoxin-producing molds were determined. A great variability was observed in the composition of the essential oils obtained from the six aromatic plants. The Cistus ladanifer essential oil had the highest content of total phenols (287.32 ppm), followed by the Cistus salviifolius essential oil; and the Rosmarinus officinalis essential oil showed the lowest amount of these compounds. The essential oils showed inhibitory effects on the tested bacteria and also yeasts, showing a maximum inhibition diameter of 11.50 mm for Salmonella choleraesuis and Kregervanrija fluxuum in the case of Cistus ladanifer and a maximum diameter of 9 mm for Bacillus cereus and 9.50 mm for Priceomyces carsonii in the case of Cistus salviifolius. The results stated that antibacterial and antiyeast activity is influenced by the concentration and the plant material used for essential oil preparation. In molds, aflatoxin production was inhibited by all the essential oils, especially the essential oils of Cistus ladanifer and Cistus salviifolius. Therefore, it can be concluded that the essential oils of native plants have significant antimicrobial properties against pathogenic and spoilage microorganisms, so they could be studied for their use in the industry as they are cheap, available, and non-toxic plants that favor the sustainability of the environment of the Dehesa of Extremeña.


Asunto(s)
Aflatoxinas , Aceites Volátiles , Aceites Volátiles/farmacología , Antibacterianos/farmacología , Fenoles , Pruebas de Sensibilidad Microbiana
13.
Emerg Infect Dis ; 29(1): 154-159, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36573593

RESUMEN

Pfhrp2 and pfhrp3 gene deletions threaten the use of Plasmodium falciparum malaria rapid diagnostic tests globally. In South Sudan, deletion frequencies were 15.6% for pfhrp2, 20.0% for pfhrp3, and 7.5% for double deletions. Deletions were approximately twice as prevalent in monoclonal infections than in polyclonal infections.


Asunto(s)
Malaria Falciparum , Plasmodium falciparum , Humanos , Plasmodium falciparum/genética , Antígenos de Protozoos/genética , Proteínas Protozoarias/genética , Eliminación de Gen , Sudán del Sur , Pruebas Diagnósticas de Rutina , Malaria Falciparum/diagnóstico , Malaria Falciparum/epidemiología
14.
ACS Omega ; 7(49): 45096-45106, 2022 Dec 13.
Artículo en Inglés | MEDLINE | ID: mdl-36530270

RESUMEN

Broccoli extract mainly contains polyphenols and glucosinolates (GSLs). GSLs can be hydrolyzed by gut microorganisms into isothiocyanates (ITCs) and other active substances. These substances have anticancer, anti-inflammatory, antimicrobial, and atherosclerosis-reducing functions. In this study, a high concentration (2000 µmol/L GSLs and 24 µmol/L polyphenols) and a low concentration (83 µmol/L GSLs and 1 µmol/L polyphenols) of broccoli extract were prepared. Gut microorganisms from fresh human feces were cultured to simulate the gut environment in vitro. The GSL content decreased and the types and content of ITCs increased with broccoli extract hydrolysis through cyclic condensation and gas chromatography-mass spectrometry (GC-MS) analyses. Broccoli extract significantly increased probiotics and inhibited harmful bacteria through 16S rDNA sequencing. Based on phylum level analysis, Firmicutes and Lachnospiraceae increased significantly (P < 0.05). At the genus level, both high- and low-concentration groups significantly inhibited Escherichia and increased Bilophila and Alistipes (P < 0.05). The high-concentration group significantly increased Bifidobacterium (P < 0.05). The broccoli extract improved the richness of gut microorganisms and regulated their structure. The GSL hydrolysis was significantly correlated with Bilophila, Lachnospiraceae, Alistipes, Bifidobacterium, Escherichia, and Streptococcus (P < 0.05). These study findings provide a theoretical foundation for further exploring a probiotic mechanism of broccoli extract in the intestine.

15.
Eng Comput ; 38(5): 4135-4149, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36397878

RESUMEN

The correct function of many organs depends on proper lumen morphogenesis, which requires the orchestration of both biological and mechanical aspects. However, how these factors coordinate is not yet fully understood. Here, we focus on the development of a mechanistic model for computationally simulating lumen morphogenesis. In particular, we consider the hydrostatic pressure generated by the cells' fluid secretion as the driving force and the density of the extracellular matrix as regulators of the process. For this purpose, we develop a 3D agent-based-model for lumen morphogenesis that includes cells' fluid secretion and the density of the extracellular matrix. Moreover, this computer-based model considers the variation in the biological behavior of cells in response to the mechanical forces that they sense. Then, we study the formation of the lumen under different-mechanical scenarios and conclude that an increase in the matrix density reduces the lumen volume and hinders lumen morphogenesis. Finally, we show that the model successfully predicts normal lumen morphogenesis when the matrix density is physiological and aberrant multilumen formation when the matrix density is excessive. Supplementary Information: The online version contains supplementary material available at 10.1007/s00366-022-01654-1.

17.
Eur J Cell Biol ; 101(3): 151255, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35843121

RESUMEN

Cell migration is essential for a variety of biological processes, such as embryogenesis, wound healing, and the immune response. After more than a century of research-mainly on flat surfaces-, there are still many unknowns about cell motility. In particular, regarding how cells migrate within 3D matrices, which more accurately replicate in vivo conditions. We present a novel in silico model of 3D mesenchymal cell migration regulated by the chemical and mechanical profile of the surrounding environment. This in silico model considers cell's adhesive and nuclear phenotypes, the effects of the steric hindrance of the matrix, and cells ability to degradate the ECM. These factors are crucial when investigating the increasing difficulty that migrating cells find to squeeze their nuclei through dense matrices, which may act as physical barriers. Our results agree with previous in vitro observations where fibroblasts cultured in collagen-based hydrogels did not durotax toward regions with higher collagen concentrations. Instead, they exhibited an adurotactic behavior, following a more random trajectory. Overall, cell's migratory response in 3D domains depends on its phenotype, and the properties of the surrounding environment, that is, 3D cell motion is strongly dependent on the context.


Asunto(s)
Colágeno , Matriz Extracelular , Movimiento Celular/fisiología , Colágeno/análisis , Colágeno/química , Matriz Extracelular/química , Fibroblastos , Cicatrización de Heridas
18.
Cell Adh Migr ; 16(1): 25-64, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-35499121

RESUMEN

Cell motility is essential for life and development. Unfortunately, cell migration is also linked to several pathological processes, such as cancer metastasis. Cells' ability to migrate relies on many actors. Cells change their migratory strategy based on their phenotype and the properties of the surrounding microenvironment. Cell migration is, therefore, an extremely complex phenomenon. Researchers have investigated cell motility for more than a century. Recent discoveries have uncovered some of the mysteries associated with the mechanisms involved in cell migration, such as intracellular signaling and cell mechanics. These findings involve different players, including transmembrane receptors, adhesive complexes, cytoskeletal components , the nucleus, and the extracellular matrix. This review aims to give a global overview of our current understanding of cell migration.


Asunto(s)
Citoesqueleto , Matriz Extracelular , Membrana Celular , Movimiento Celular , Matriz Extracelular/metabolismo , Transducción de Señal
19.
Int J Food Microbiol ; 373: 109703, 2022 Jul 16.
Artículo en Inglés | MEDLINE | ID: mdl-35561525

RESUMEN

The present work was performed to study the enterobacteria involved in the ripening of the artisanal raw ewe's milk PDO cheeses 'Torta del Casar' and 'Queso de la Serena' produced in Extremadura (Spain). These isolates were strain-typed, safety tested and characterized for some important technological properties. A total of 485 enterobacterial isolates were clustered by RAPD-PCR and subsequently identified by partial sequencing of the 16S rRNA gene. Among the 17 different species identified, Hafnia paralvei was the predominant species; H. alvei and Lelliottia amnigena were present to a lesser extent. Therefore, 55 Hafnia spp. strains, selected according to their genetic profile and dairy origin, were tested for the safe application. Overall, they were able to produce the biogenic amines putrescine and cadaverine under favourable conditions, presented α-haemolytic activity and did not produce cytolytic toxin active against HeLa cells or contain virulence genes. In addition, antibiotic susceptibility profiles showed that 17 Hafnia spp. strains were less resistant to the 33 antibiotics tested; subsequently, they were further technologically characterized. Although they showed differences, in general, they were well adapted to the stress conditions of cheese ripening. Among them, two strains, H. alvei 544 and 1142, are highlighted mainly due to their proteolytic activity at refrigeration temperatures and their low or null gas production. Although further studies are necessary before industrial application, these two strains are proposed for potential use as adjunct cultures to favour the homogeneity of these PDO cheeses, preserving their unique sensory characteristics.


Asunto(s)
Queso , Hafnia , Animales , Queso/microbiología , Femenino , Hafnia/genética , Células HeLa , Humanos , Leche/microbiología , ARN Ribosómico 16S/genética , Técnica del ADN Polimorfo Amplificado Aleatorio , Ovinos/genética
20.
J Dairy Sci ; 105(4): 2931-2947, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35123784

RESUMEN

The yeasts involved in the ripening process of artisanal soft raw ewe milk Protected Designation of Origin (PDO) Torta del Casar and Queso de la Serena cheeses produced in Extremadura, Spain, were isolated throughout their ripening process, strain typed, and characterized for some important technological properties. A total of 508 yeast isolates were obtained and identified by inter-single sequence repeat anchored PCR amplification analysis and subsequent sequencing of the internal transcribed spacer ITS1/ITS2 5.8S rRNA. A total of 19 yeast species representing 8 genera were identified. Debaryomyces hansenii, Pichia kudriavzevii, Kluyveromyces lactis, and Yarrowia lipolytica were the predominant species. We selected 157 isolates, by genotyping and origin, for technological characterization. The evaluation of yeast isolates' growth under stress conditions of cheese ripening showed that 87 presented better performance. Among them, 71 isolates were not able to catabolize tyrosine to produce a brown pigment. Principal component analysis of the biochemical features of these isolates showed that 9 strains stood out, 3 K. lactis strains (2287, 2725, and 1507), 2 Pichia jadinii (1731 and 433), 2 Yarrowia alimentaria (1204 and 2150), Y. lipolytica 2495 and P. kudriavzevii 373. These strains displayed strong extracellular proteolytic activity on skim milk agar as well as an adequate enzymatic profile (strong aminopeptidase and weak protease activity), suggesting their great potential for cheese proteolysis. Extracellular lipolytic activity was mainly restricted to Yarrowia spp. isolates and weakly present in P. kudriavzevii 373 and K. lactis 2725, although enzymatic characterization by API-ZYM (bioMérieux SA) evidenced that all may contribute, at least in part, to the lipolysis process. Moreover, these strains were able to assimilate lactose, galactose, and glucose at NaCl concentrations higher than that usually found in cheese. However, lactate and citrate assimilation were limited to Y. lipolytica 2495, P. kudriavzevii 373, and P. jadinii 433, and may contribute to the alkalinizing process relevant to biochemical processes that take place in the last stages of ripening. By contrast, K. lactis strains showed acidifying capacity and ß-galactosidase activity and may take part in the initial stages of ripening, together with lactic acid bacteria. Thus, considering the technological characteristics studied, the 9 selected strains presented biochemical features well suited to their potential use as adjunct cultures, alone or in combination with autochthonous starter bacteria in the cheesemaking process, to overcome the heterogeneity of these PDO cheeses, preserving their unique sensory characteristics.


Asunto(s)
Queso , Animales , Candida , Queso/microbiología , Microbiología de Alimentos , Leche/microbiología , Ovinos , Levaduras
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